Methods, wireless communication station, and system for WLAN channel selection through beacon requests

ABSTRACT

Embodiments of a user station (STA) and methods for WLAN channel selection through beacon requests are generally described herein. In some embodiments, a STA requests that an access point (AP) transmit a beacon signal on a first sub-band. The first sub-band may include a channel of interest to the STA. The STA may determine that the AP supports the first sub-band if the AP transmits the requested beacon signal.

TECHNICAL FIELD

Embodiments pertain to communication networks. Some embodiments pertainto wireless devices operating in wireless local area networks (WLANs) inaccordance with Institute of Electrical and Electronics Engineers (IEEE)802.11 family of standards.

BACKGROUND

The IEEE has adopted a set of standards for WLANs, known as 802.11.Under 802.11, a user device, also known as a user station (STA), mayaccess a WLAN through an access point (AP). The user STA may transmit inthose sub-bands of the regulatory WLAN frequency spectrum in which theuser STA has already received signaling from the AP. Therefore, sub-banduse may be limited according to the signaling provided by the AP.

Accordingly, there is a general need for a user STA to perform methodsto switch sub-bands for transmission based on the needs of the user STA.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a wireless local area network (WLAN) in which exampleembodiments are implemented;

FIG. 2 is a flow diagram of a procedure performed by a user STA foroperation in a wireless communication network, in accordance with someembodiments;

FIG. 3 illustrates a beacon request frame in accordance with someembodiments;

FIG. 4 illustrates a functional block diagram of a communication station(STA), in accordance with some embodiments;

FIG. 5 is a flow diagram of a procedure for switching from a firstsub-band to a second sub-band in a wireless communication network inaccordance with some embodiments; and

FIG. 6 is a flow diagram of a procedure performed by an access point(AP) for operating in a wireless communication network in accordancewith some embodiments.

DETAILED DESCRIPTION

The following description and the drawings sufficiently illustratespecific embodiments to enable those skilled in the art to practicethem. Other embodiments may incorporate structural, logical, electrical,process, and other changes. Portions and features of some embodimentsmay be included in, or substituted for, those of other embodiments.Embodiments set forth in the claims encompass all available equivalentsof those claims.

FIG. 1 illustrates a user wireless communication station (STA) 110. Theuser STA 110 may be, for example, a laptop computer, a smart phone, atablet computer, or any other wireless device. In an example, the userSTA 110 has a wireless connection 115 through a second STA 120 to thenetwork 125. The second STA 120 may be a more stationary communicationunit such as a wireless access point (AP) and will hereinafter bereferred to as the AP 120. The network 125 may be a home network, anenterprise network, the Internet, or any other suitable network. In someembodiments, the user STA 110 and the AP 120 may transmit and/or receivecommunications in accordance with specific communication standards, suchas the IEEE 802.11 standards although user STA 110 and the AP 120 mayalso be suitable to transmit and/or receive communications in accordancewith other techniques.

The user STA 110 may further have connections 130 and 135 to otherwireless devices such as, for example, a printer 140 and a camera 145.However, any number of wireless devices, or no wireless devices, mayhave connections to the user STA 110. The user STA 110 may act or becapable of acting as a peer-to-peer (P2P) group owner (GO) of the groupcomprised of the printer 140, the user STA 110, the camera 145 or otherwireless devices (not shown).

The user STA 110 may be arranged to operate on a first set of one ormore sub-bands within a WLAN spectrum. The AP 120 may be arranged tooperate on a second set of one or more sub-bands within the WLANspectrum. The WLAN spectrum may include channels within frequency rangesspecified in accordance with a standard of the 802.11 family ofstandards. For example, the WLAN spectrum may include channels orsub-bands within a 2.4-gigahertz (GHz) band, a 5-GHz band, or a 60-GHzband. The first set of sub-bands, supported by the user STA 110, mayinclude the same sub-bands that are included in the second set ofsub-bands supported by the AP 120. Alternatively, the first set mayinclude more sub-bands than the second set, or the second set mayinclude more sub-bands than the first set.

The allowable WLAN spectrum may vary based on geographic considerations.For example, national regulations may permit spectrum usage at 5.8 GHzin the United States, while the 5.8 GHz band may not be used in theEuropean Union. Some equipment manufacturers therefore may providedifferent STAs for usage in different geographical locations. Otherequipment manufacturers may provide a “worst-case scenario” STA that canfunction in any geographical location, on a reduced set of sub-bands orwith reduced functionality. Accordingly, logistical supply complicationsmay be introduced, or the user experience may be degraded.

Under some reduced functionalities, a user STA 110 may not transmit on asub-band or channel unless or until the user STA 110 has observed orreceived a beacon signal from an AP 120 on that sub-band. Accordingly,the user STA 110 is limited to transmissions on particular sub-bands forwhich the AP 120 has transmitted a beacon signal. However, either orboth of the AP 120 and the user STA 110 may support communications onother sub-bands. Additionally, conditions may be advantageous to theuser STA 110 on other sub-bands besides those sub-bands on which the AP120 is transmitting beacon signals. For example, other sub-bands mayhave reduced or no traffic or provide better channel quality.

In accordance with example embodiments, therefore, the user STA 110 mayrequest that the AP 120 transmit a beacon signal on a given sub-band, sothat the user STA 110 may thereafter communicate over that sub-band.FIG. 2 illustrates a method, performed by the user STA 110, foroperating in a wireless network.

Referring to FIG. 2, in operation 200, the user STA 110 may request thatan AP 120 transmit a beacon signal on a first sub-band. The firstsub-band may include a channel of interest to the user STA 110. The userSTA 110 may request the beacon signal by transmitting a beacon requestframe to the AP 120. The user STA 110 may transmit the beacon requestframe on a second sub-band. The second sub-band may be a sub-band onwhich the AP 120 has already transmitted a beacon signal, thuspermitting user STA 110 transmissions on the second sub-band. A beaconrequest frame in accordance with example embodiments is shown in FIG. 3.

Referring to FIG. 3, the beacon request frame may include a sub-field300 indicating the identity of the first sub-band for which the user STA110 is requesting a beacon signal. The beacon request frame may includeadditional fields in accordance with a standard of the IEEE 802.11family of standards.

Referring again to FIG. 2, in operation 210, the user STA 110 maydetermine that the AP 120 supports the first sub-band if the AP 120transmits the requested beacon signal. The user STA 110 may determinethat the AP 120 does not support the first sub-band if the AP 120indicates that the AP 120 does not support the first sub-band or if noresponse is received to the beacon request frame within a time duration.Upon determining that the AP 120 does not support the first sub-band,the user STA 110 may transmit a beacon request frame to request a beaconsignal on a different sub-band. The different sub-band may include adifferent channel of interest to the user STA 110.

The user STA 110 may determine a sub-band for which to requesttransmission of the beacon signal based on geographically specificsignaling from the AP 120. The geographically specific signaling may be,for example, country information signaling according to a standard ofthe IEEE 802.11 family of standards.

FIG. 4 illustrates a functional block diagram of a STA 400, inaccordance with some embodiments. The STA 400 may be suitable as a userSTA 110 (FIG. 1) or as an AP 120 (FIG. 1). The STA 400 may supportmethods for operating in a wireless communication network, in accordancewith embodiments. The STA 400 may include a processor 402, which uses achip set 404 to access on-chip state memory 406, as well as acommunications interface 408. In one embodiment the memory 406 includes,but is not limited to, random access memory (RAM), dynamic RAM (DRAM),static RAM (SRAM), synchronous DRAM (SDRAM), double data rate (DDR)SDRAM (DDR-SDRAM), or any device capable of supporting high-speedbuffering of data.

In at least one embodiment, the communications interface 408 is, forexample, a wireless Physical Layer (PHY), which operates according to amultiple input/multiple output (MIMO) operation. The communicationsinterface 408 may receive geographical information. The geographicalinformation may be received from the AP 120. When the STA 400 acts as auser STA 110 (FIG. 1), the communications interface 408 may use a firstsub-band to transmit the beacon request frame to a second STA. Asdiscussed above, the second STA may be the AP 120. The beacon requestframe may request that the AP 120 transmit a beacon signal on a secondsub-band. The communications interface 408 may receive, on the secondsub-band, a beacon signal in response to the beacon request frame. Thecommunications interface 408 may receive geographical information. Thegeographical information may be received from the AP 120. Thecommunications interface 408 may receive an acknowledgement (ACK) fromthe AP 120 in response to the beacon request frame.

The chip set 404 may incorporate therein Beacon Request Logic 412 to,for example, configure a beacon request frame or to configure a responseto a beacon request frame. In an embodiment, the chipset 404 providesMAC layer functionality. For example, the chipset 404 may provide MAClayer functionality to configure a beacon request frame or to configurea response to a beacon request frame.

When the STA 400 operates as a user STA 120, the processor 402 may bearranged to determine the sub-band for which to transmit the beaconrequest frame based on a channel of interest of the STA 400. Theprocessor 402 may be arranged to select the channel of interest based ongeographical information received through the communications interface408. The processor 402 may determine that the requested sub-band is notsupported if the communications interface 408 does not receive therequested beacon signal within a time duration. The processor 402 maydetermine that the requested sub-band is not supported if thecommunications interface 408 does not receive the requested beaconsignal within a time duration after the communications interface 408received the ACK to the beacon request frame.

When the STA 400 operates as an AP 120 (FIG. 1), the communicationsinterface 408 may receive, on a first sub-band, a beacon request framerequesting transmission of a beacon signal on a second sub-band. Thecommunications interface 408 may transmit the beacon signal on thesecond sub-band upon determining whether to support communication on thesecond sub-band. The communications interface 408 may transmit, on thesecond sub-band, an acknowledgement (ACK) message in response to thebeacon request frame. The communications interface 408 may transmit, onthe first sub-band, a response denying service on the second sub-band.

When the STA 400 operates as an AP 120, the processor 402 may determinewhether to support communication in the second sub-band. Thecommunications interface 408 may transmit the beacon signal within atime duration of the transmission of the ACK message upon determinationby the processor 402 to support communication in the second sub-band.

Embodiments may be implemented in one or a combination of hardware,firmware and software. Embodiments may also be implemented asinstructions 414 stored on a computer-readable storage device, which maybe read and executed by at least one processor 402 to perform theoperations described herein. In some embodiments, the instructions 414are stored on the processor 402 or the memory 406 such that theprocessor 402 and the memory 406 act as computer-readable mediums. Acomputer-readable storage device may include any non-transitorymechanism for storing information in a form readable by a machine (e.g.,a computer). For example, a computer-readable storage device may includeROM, RAM, magnetic disk storage media, optical storage media,flash-memory devices, and other storage devices and media.

Although the STA 400 is illustrated as having several separatefunctional elements, one or more of the functional elements may becombined and may be implemented by combinations of software-configuredelements, such as processing elements including digital signalprocessors (DSPs) and/or other hardware elements. For example, someelements may comprise one or more microprocessors, DSPs, applicationspecific integrated circuits (ASICs), radio-frequency integratedcircuits (RFICs), and combinations of various hardware and logiccircuitry for performing at least the functions described herein. Insome embodiments, the functional elements of the STA 400 may refer toone or more processes operating on one or more processing elements.

The STA 400 may include multiple transmit and receive antennas 410-1through 410-N, where N is a natural number. Antennas 410-1 through 410-Nmay comprise one or more directional or omnidirectional antennas,including, for example, dipole antennas, monopole antennas, patchantennas, loop antennas, microstrip antennas, or other types of antennassuitable for transmission of RF signals. In some embodiments, instead oftwo or more antennas, a single antenna with multiple apertures may beused. In these embodiments, each aperture may be considered a separateantenna. In some MIMO embodiments, antennas 410-1 through 410-N may beeffectively separated to take advantage of spatial diversity and thedifferent channel characteristics that may result between each ofantennas 410-1 through 410-N and the antennas of an originator STA. Insome MIMO embodiments, antennas 410-1 through 410-N may be separated byup to 1/10 of a wavelength or more.

FIG. 5 illustrates a method, performed by the user STA 110, forswitching from a first sub-band to a second sub-band in a wirelesscommunication network. In operation 500, the user STA 110 may determinethat a channel on the second sub-band is not in use. In operation 510,the user STA 110 may request that a beacon signal be transmitted on thesecond sub-band. The request may include transmission, on the firstsub-band, of a request signal as described above with respect to FIG. 3.In operation 520, the user STA 110 may transmit at least one frame onthe channel in the second sub-band upon receiving the requested beaconsignal in the second sub-band. The user STA 110 may further become apeer-to-peer (P2P) group owner (GO), over a group comprising, forexample, the printer 140 (FIG. 1), the camera 145 (FIG. 1) or otherwireless devices (not shown). The user STA 110 may become a GO bytransmitting a beacon signal on the second sub-band to the printer 140,the camera 145, or to other wireless devices. As the GO, the user STA110 may establish associations with and communications between theprinter 140, the camera 145, or other wireless devices.

FIG. 6 illustrates a method, performed by the AP 120, of operating in awireless communication network. In operation 600, the AP 120 may receivea request to transmit a beacon signal on a first sub-band. In operation610, the AP 120 may determine whether the AP 120 can perform APfunctions on the first sub-band. In operation 620, the AP 120 maytransmit the requested beacon signal on the first sub-band if the AP 120determines that the AP 120 might possibly perform AP functions on thefirst sub-band.

In at least one embodiment, if the AP 120 decides the AP 120 cannotsupport AP functions on the first sub-band, the AP 120 may transmit aresponse denying service on the first sub-band. The AP 120 may transmitthis response on a sub-band at which the AP 120 is already providingservice. For example, the AP 120 may transmit this response on thesub-band on which the AP 120 received the request for the beacon signal.In at least another embodiment, the AP 120 may ignore the request forthe beacon signal if the AP 120 decides the AP 120 cannot support APfunctions on the first sub-band. The AP 120 may limit determinations ofwhether to perform AP functions on the first sub-band. For example, theAP 120 may limit the number of determinations made to a certain maximumover a time interval. Further, or in addition, the AP 120 may limittransmissions of the requested beacon signal to a number oftransmissions within a time interval. The AP 120 may transmit anacknowledgement (ACK) message upon receiving a request for a beaconsignal.

The Abstract is provided to comply with 37 C.F.R. Section 1.72(b)requiring an abstract that will allow the reader to ascertain the natureand gist of the technical disclosure. It is submitted with theunderstanding that it will not be used to limit or interpret the scopeor meaning of the claims. The following claims are hereby incorporatedinto the detailed description, with each claim standing on its own as aseparate embodiment.

What is claimed is:
 1. A method, performed by a user station (STA), foroperating in a wireless network, the method comprising: receiving atleast one beacon signal frame on a first sub-band; requesting that anaccess point (AP) transmit a beacon signal on a second sub-bandsubsequent to and conditioned upon receiving the at least one beaconsignal frame on the first sub-band, wherein the requesting includestransmitting a request signal on the first sub-band, wherein the secondsub-band is different from the first sub-band, the second sub-bandincluding a channel of interest to the STA; and determining that the APsupports the second sub-band if the AP transmits the requested beaconsignal on the second sub-band.
 2. The method of claim 1, wherein therequest signal includes a field indicating the second sub-band.
 3. Themethod of claim 1, further comprising: determining that the AP does notsupport the second sub-band if the AP indicates that the AP does notsupport the second sub-band or if no response is received to therequesting within a time duration.
 4. The method of claim 3, furthercomprising: upon determining that the AP does not support the secondsub-band, requesting that the AP transmit a beacon signal on a thirdsub-band, the third sub-band including a second channel of interest tothe STA.
 5. The method of claim 1, wherein the STA determines thesub-band for which to request transmission of the beacon signal based ongeographically-specific signaling from the AP.
 6. The method of claim 5,wherein the geographically-specific signaling is country informationsignaling according to a standard of the Institute of Electrical andElectronics Engineers (IEEE) 802.11 family of standards.
 7. A wirelesscommunication station (STA) comprising: a medium access control (MAC)layer to configure a beacon request frame; physical layer (PHY)circuitry to receive at least one beacon signal frame on a firstsub-band; transmit, on the first sub-band, the beacon request frame to asecond STA, subsequent to and conditioned upon receiving the at leastone beacon signal frame on the first sub-band, and receive, on a secondsub-band, a beacon signal in response to the beacon request frame,wherein the first sub-band is different from the second sub-band; andone or more processors to determine the second sub-band for which totransmit the beacon request frame based on a channel of interest of theSTA.
 8. The STA of claim 7, wherein the PHY circuitry is furtherarranged to receive geographical information, and the one or moreprocessors are further arranged to select the channel of interest basedon the geographical information.
 9. The STA of claim 7, wherein the oneor more processors determines that the second STA does not support thesecond sub-band if the PHY circuitry does not receive the beacon signalwithin a time duration.
 10. The STA of claim 7, wherein the PHYcircuitry is further arranged to receive an acknowledgement (ACK) inresponse to the beacon request frame.
 11. The STA of claim 10, whereinthe processor determines that the second STA does not support the secondsub-band if the PHY circuitry does not receive the beacon signal withina time duration after receiving the ACK.
 12. A method, performed by auser device station (STA), for switching from a first sub-band to asecond sub-band in a wireless communication network, the methodcomprising: receiving at least one beacon signal frame on the firstsub-band; determining that a channel on the second sub-band is not inuse; requesting that a beacon signal be transmitted on the secondsub-band, subsequent to and conditioned upon receiving the at least onebeacon signal frame on the first sub-band, wherein the second sub-bandis different from the first sub-band, and wherein the requestingincludes transmitting a request signal, on the first sub-band, to asecond device; and transmitting at least one frame on the channel in thesecond sub-band upon receiving the requested beacon signal in the secondsub-band.
 13. The method of claim 12, wherein the requesting comprises:transmitting, on the first sub-band, a request including a fieldindicating the second sub-band.
 14. The method of claim 12, furthercomprising: transmitting a beacon signal on the second sub-band, uponreceiving the requested beacon signal, to become a peer-to-peer (P2P)group owner (GO) on the second sub-band.
 15. A method, performed by awireless access point (AP), of operating in a wireless communicationnetwork, the method comprising: receiving a request, from a user station(STA), to transmit a beacon signal on a first sub-band, wherein therequest is received from the STA on a second sub-band, different fromthe first sub-band, and on which the AP has previously transmitted atleast one beacon signal frame on the second sub-band prior to receivingthe request; determining whether the AP can support AP functions on thefirst sub-band; and transmitting the requested beacon signal on thefirst sub-band if the determining determines that the AP can support APfunctions on the first sub-band.
 16. The method of claim 15, furthercomprising: transmitting, on a second sub-band, a response denyingservice if the determining determines not supporting AP functions on thefirst sub-band.
 17. The method of claim 15, further comprising: ignoringthe request if the determining determines not supporting AP functions onthe first sub-band.
 18. The method of claim 15, further comprising:limiting determination of whether the AP can support AP functions on thefirst sub-band to a number of determinations within a time interval. 19.The method of claim 15, further comprising: limiting transmission of therequested beacon signal to a number of transmissions within a timeinterval.
 20. A first system comprising: an antenna arranged to receivetransmissions from a second system on a first sub-band; and a processorarranged to determine whether the second system supports a secondsub-band, different from the first sub-band, based on whether a beaconsignal is received from the second system, on the second sub-band, inresponse to a request for a beacon signal, wherein the request istransmitted on the first sub-band, and wherein transmission of therequest is conditioned on whether the second system has transmitted atleast one beacon signal frame on the first sub-band prior the firstsystem transmitting the request.
 21. The system of claim 20, wherein theprocessor is further arranged to determine the second sub-band for whichto request the beacon signal based on country information signalingreceived from the second system.
 22. A first wireless communicationstation (STA) comprising: a medium access control (MAC) layer toconfigure a response to a beacon request frame; physical layer (PHY)circuitry to receive, on a first sub-band from a requesting STA, abeacon request frame requesting transmission of a beacon signal on asecond sub-band different from the first sub-band, wherein the first STAhas transmitted at least one beacon signal frame on the first sub-band,and transmit a beacon signal on the second sub-band upon determiningwhether the first STA can support communication on the second sub-band;and one or more processors to determine whether the first STA cansupport communication on the second sub-band.
 23. The first STA of claim22, wherein the PHY circuitry is further arranged to: transmit, on thesecond sub-band, an acknowledgment (ACK) message in response to thebeacon request frame; and transmit the beacon signal within a timeduration of transmission of the ACK message upon the one or moreprocessors determining the first STA can support communication in thesecond sub-band.
 24. The first STA of claim 22, wherein the PHYcircuitry is further arranged to transmit, on the first sub-band, aresponse denying service on the second sub-band upon the one or moreprocessors determining to not support communication on the secondsub-band.